Just like carrying a pregnancy to term. Especially in the US which has a very high maternal mortality rate.
> if they are, then abortion is murder, right?
If I'm giving someone a blood transfusion because their kidneys are failing and they'll die within minutes/hours if I stop, is it murder to disconnect us? Maybe so but I should still have the right to choose. I can only recommend this video which makes the point much better than I ever could https://www.youtube.com/watch?v=c2PAajlHbnU
> Abortion definitely takes away any possibility of living from another person.
This seems to contradict your idea that a fetus is already living in the first place? And if it is already living than just like organ donation, carrying the pregnancy to term "_might_ give another person a chance at living longer" just like organ donation. Remember miscarriages are common, stillbirths are common, dying in infancy is common. Organ/blood donation is extremely comparable to being pregnant if a fetus is alive: they are alive at the grace of and only because of your body.